The Detroit Aircraft Corporation was incorporated in Detroit, Michigan on July 10, 1922, as the Aircraft Development Corporation. The name was changed in 1929. The Detroit corporation owned the entire capital stock of the Ryan Aircraft Corp., Aircraft Development Corp., Aviation Tool Co., Grosse Ile Airport, Inc., Marine Aircraft Corp., Park's Air College and Affiliated Companies, Detroit Aircraft Export Co., Gliders, Inc., and Eastman Aircraft Corp. It also owned a 90% interest in the Blackburn Aeroplane and Motor Company, practically all of the capital stock of the Lockheed Aircraft Company and a 40% interest in Winton Aviation Engine Co. During the Great Depression the Detroit Aircraft holding company found that rising losses from other operations were draining the company coffers. On O